Page content

Compasses and Calipers

Tools for making precise measurements

During the 18th century, compasses and calipers were frequently used to measure and fit work. Many products' designs were based on the proportional relationships between their parts stepped off with a compass rather than on measurements expressed in feet or inches.

Compasses also were used to draw circles and to make geometric calculations. More importantly, compasses and calipers were the standard tools for transferring a dimension from a pattern or work piece to another location.

Coopers' compasses were large compasses with a wing that could be locked at the desired position. Many types of woodworkers used compasses of this design.

Smaller compasses were made in different styles. The most common had hinged joints.

Trammel points, another form of compass, had two or more heads that could be positioned along a bar. They were used to lay out large arcs and circles.

Calipers were used to measure and transfer outside dimensions of workpieces, especially if they were curved or round. Calipers were available in many of the same styles as compasses.